text: The theorem applies to two-dimensional flow around a fixed airfoil (or any shape of infinite span).  The lift per unit span of the airfoil is given by
  where  and  are the fluid density and the fluid velocity far upstream of the airfoil, and  is the circulation defined as the line integral
  around a closed contour  enclosing the airfoil and followed in the negative (clockwise) direction.  As explained below, this path must be in a region of potential flow and not in the boundary layer of the cylinder. The integrand  is the component of the local fluid velocity in the direction tangent to the curve , and  is an infinitesimal length on the curve .  Equation  is a form of the Kutta–Joukowski theorem.
  Kuethe and Schetzer state the Kutta–Joukowski theorem as follows:
  :The force per unit length acting on a right cylinder of any cross section whatsoever is equal to  and is perpendicular to the direction of